1. Field of the Invention
The present invention relates to a data processing method and apparatus, and more particularly, to a data processing method and apparatus for reconstructing certain information from a plurality of object streams, each including predetermined information.
2. Description of the Related Art
Recently, the so-called MPEG-4 is being adopted as a standard method for combining multimedia data including a plurality of objects, such as a moving image, audio and the like, and transmitting resultant data in the form of a single bit stream. The MPEG-4 reception (reproduction) side reproduces, for example, audio and a moving-image scene in a correlated state. In a MPEG-4 reproducing apparatus, in order to protect intellectual property rights such as copyright, it is necessary to provide various types of limitations of use for the entirety or a part of such data.
In general, in order to protect copyright, it has been necessary, for example, to perform cryptographic processing for data to be transmitted, or transmit processed data obtained by embedding data as an electronic transparency at the transmission side. At the reception side, i.e., the reproducing apparatus side, it is arranged to obtain information for deciphering (decoding) a cipher or information necessary for authentication of an electronic transparency, and to decode and reproduce data including a desired moving image and audio from data processed in the above-described manner, when, for example, a proper fee has been paid for the copyright. In an operation of deciphering a cipher or authenticating an electronic transparency, copyright is protected by limiting the number of operations of copying data or prohibiting editing with other objects.
For the above-described MPEG-4 data stream, in contrast to the case of conventional ordinary multimedia data, the function of transmitting/receiving a plurality of video scenes and video projects independently in a single stream is provided. Similarly, as for audio data, a plurality of objects can be reconstructed from a single stream. That is, a MPEG-4 data stream includes a BIFS (binary format for scenes) developed from a VRML (virtual reality modeling language) as information for synthesizing a plurality of scenes. The BIFS is information in which a MPEG-4 scene is described with binary values.
Each of objects necessary for synthesizing the plurality of scenes is subjected to optimum encoding and is transmitted. The decoding side decodes the transmitted data, and reproduces original data by synthesizing scenes by synchronizing the time base of each data with the time base within the reproducing apparatus in accordance with the description of the BIFS.
As described above, in the MPEG-4 method or the like, since a plurality of video objects and scenes are synthesized, it is necessary to provide limitation of use for each copyright. For that purpose, the assignee of the present application has proposed, in Japanese Patent Laid-Open Application (Kokai) No. 10-295937 (1998), a system in which information relating to authentication for the use of copyright is obtained for each object.
However, there has not been proposed a specific approach when not reproducing a specific object authenticated not to be used, or when resuming an operation of decoding or reproducing an object, for which reconstruction or reproduction is interrupted due to an operation of authenticating a regular user (a user who has paid a proper fee), again in synchronization with other objects.
Particularly, if the object for which a decoding or reproducing operation has been interrupted is a moving-image object and is not synchronized with an audio object for which reproduction is continued during that period, so-called lip synchronism is not provided, thereby causing distraction for the viewer. Furthermore, since the amount of data of a moving-image object is generally large, how to economize power consumption during interruption of an operation of decoding the object is a significant problem.
As described above, in processing conforming to MPEG-4 or the like in which a plurality of objects constituting a scene are separately processed, synchronism between a plurality of sets of information when resuming the processing after interruption of an operation of processing a part of the information in order to protect copyright or due to disturbance, noise or the like in satellite communication or the like has become a significant problem.
It is an object of the present invention to solve the above-described problems.
It is another object of the present invention to provide a data processing method and apparatus in which, even if reconstruction of a part of information is interrupted when reconstructing information from a data stream including a plurality of object streams, synchronism between a plurality of sets of information can be obtained after resuming the reconstruction operation.
According to one aspect of the present invention, a data processing method includes the steps of separaing each object stream from a data stream including a plurality of object streams, each having predetermined information, reproducing synthesis information obtained by synthesizing respective sets of information of the plurality of object streams, and controlling pause and execution of an operation of reproducing one of the plurality of object streams. In the controlling step, a timing of control for the one object stream is determined using time information in another object stream.
According to the above-described configuration, it is possible to assuredly provide synchronism with another information after resuming reconstruction of one information even if reconstruction of that information is interrupted.
According to another aspect of the present invention, a data processing method includes the steps of separating each object stream from a data stream including a plurality of object streams, each having predetermined information, and a control stream having scene description information for synthesizing respective sets of information included in the plurality of object streams, and management information for managing copywright of concerned information, reproducing information included in the plurality of object streams, synthesizing the respective sets of information included in the plurality of object streams based on the scene description information and outputting resultant information, and controlling pause and execution of reproducing at least one of the plurality of object streams, based on the management information. In the controlling step, a timing of control for the at least one object stream is determined using time information in another object stream.
According to still another aspect of the present invention, a data processing device includes input means for inputting a data stream including a plurality of object streams, each having predetermined information, separation means for separating each object stream from the data stream input by the input means, reconstruction means for reconstructing the predetermined information from the object stream separated by the separation means, and control means for controlling pause and execution of reconstruction of information included in an object stream from among the plurality of object streams. The cotrol means determines a timing of control for the one object stream using time information in another object stream.
According to yet another aspect of the present invention, in a data processing device including a data reproducing unit for reproducing synthesis information by separating each object stream from a data stream including a plurality of object streams, each having predetermined information, the data reproducting unit includes input means for inputting the data stream including the plurality of object streams, each having predetermined information, separation means for separating each object stream from the data stream input by the input means, reconstruction means for reconstructing the predetermined information from the object stream separated by the separation means, and control means for controlling pause and execution of reconstruction of information included in an object stream from among the plurality of object streams. The cotrol means determines a timing of control for the one object stream using time information in another object stream.
According to yet a further aspect of the present invention, a data reproducing apparatus includes input means for inputting a data stream including a plurality of object streams, each having predetermined information, and a management stream having scene description information for synthesizing respective sets of information contained in the plurality of object streams, and management information for managing copywright of concerned information, separation means for separating each object stream from the data stream input by the input means, reconstruction means for reconstructing each information separated by the separation means, reproduction means for obtaining reproduction information by synthesizing respective sets of information reconstituted by the reconstruction means based on the scene description information, and control means for controlling pause and execution of reconstruction of information included in at least one object stream from among the plurality of object streams based on the management information. The cotrol means determines a timing of an operation for the one object stream using time information in other object streams.
According to the above-described configuration, protection of copywright, and synchronism between a plurality of sets of information, such as an image and audio, can be compatible.
According to still another aspect of the present invention, in a data processing apparatus which has a data reproducing unit for reproducing synthesis information by separating each object stream from a data stream including a plurality of object streams, each having predetermined information, the data reproducing unit includes input means for inputting a data stream including a plurality of object streams, each having predetermined information, and a management stream having scene description information for synthesizing respective sets of information contained in the plurality of object streams, and management information for managing copyright of concerned information, separation means for separating each object stream from the data stream input by the input means, reconstruction means for reconstructing each information separated by the separation means, reproduction means for obtaining reproduction information by synthesizing respective sets of information reconstructed by the reconstruction means based on the scene description information, and control means for controlling pause and execution of reconstruction of information included in at least one object stream from among the plurality of object streams based on the management information. The cotrol means determines a timing of an operation for the one object stream using time information in other object streams.
According to still another aspect of the present invention, in a computer readable recording medium which stores a data processing program for separating each object stream from a data stream including a plurality of object streams, each having predetemined information, and reproducing synthesis information, the data processing program includes the step of determining, when controlling pause and execution of reproduction of one of the plurality of object streams, a control timing for the one object stream using time information in another object stream.
According to still another aspect of the present invention, in a computer readable recording medium which stores a data processing program for separating each object stream from a data stream including a plurality of object streams, each having predetemined information, and reproducing synthesis information, the data processing program includes an information input module for inputting management information, a management-information analysis module for analyzing the management information, a data-reconstruction control module for reconstructing original data from the data stream in accordance with the management information, and a reconstruction-synchronism control module for controlling synchronism of pause and execution of reproduction based on the management information. When controlling pause and execution of reproduction of one of the plurality of object streams, a control timing for the one object stream is determined using time information in another object stream.
The foregoing and other objects, advantages and features of the present invention will become more apparent from the following detalied description of the preferred embodiment taken in conjunction with the accompanying drawings.